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[Qemu-devel] [PATCH] virtio-scsi: fix "written length" field in the used
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH] virtio-scsi: fix "written length" field in the used ring |
Date: |
Mon, 27 Apr 2015 14:29:25 +0200 |
qsgl->size is the size of the data field after the request or
response header (virtio-scsi currently supports only one such
field; bidirectional requests are not supported). However,
the used ring's len field is not concerned about the field
after the request header, so do not count it unless req->mode
signals the request was a read.
Also, do not report that anything was written if the request
failed, and subtract any residual bytes in case of buffer underrun.
Signed-off-by: Paolo Bonzini <address@hidden>
---
hw/scsi/virtio-scsi.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index c9bea06..4995f6e 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -65,6 +65,19 @@ void virtio_scsi_free_req(VirtIOSCSIReq *req)
g_slice_free1(sizeof(*req) + vs->cdb_size, req);
}
+static size_t virtio_scsi_written_length(VirtIODevice *vdev, VirtIOSCSIReq
*req)
+{
+ size_t sz = req->resp_iov.size;
+
+ if (req->sreq &&
+ req->mode == SCSI_XFER_FROM_DEV &&
+ req->resp.cmd.response == VIRTIO_SCSI_S_OK) {
+ sz += req->qsgl.size - virtio_tswap32(vdev, req->resp.cmd.resid);
+ }
+
+ return sz;
+}
+
static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
{
VirtIOSCSI *s = req->dev;
@@ -76,7 +89,7 @@ static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
assert(req->vq == NULL);
virtio_scsi_vring_push_notify(req);
} else {
- virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
+ virtqueue_push(vq, &req->elem, virtio_scsi_written_length(vdev, req));
virtio_notify(vdev, vq);
}
--
2.3.5
- [Qemu-devel] [PATCH] virtio-scsi: fix "written length" field in the used ring,
Paolo Bonzini <=